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Using microsatellite data to estimate the persistence of field-level yield gaps and their drivers in smallholder systems

Balwinder-Singh Meha Jain (2023, [Artículo])

One way to meet growing food demand is to increase yields in regions that have large yield gaps, including smallholder systems. To do this, it is important to quantify yield gaps, their persistence, and their drivers at large spatio-temporal scales. Here we use microsatellite data to map field-level yields from 2014 to 2018 in Bihar, India and use these data to assess the magnitude, persistence, and drivers of yield gaps at the landscape scale. We find that overall yield gaps are large (33% of mean yields), but only 17% of yields are persistent across time. We find that sowing date, plot area, and weather are the factors that most explain variation in yield gaps across our study region, with earlier sowing associated with significantly higher yield values. Simulations suggest that if all farmers were able to adopt ideal management strategies, including earlier sowing and more irrigation use, yield gaps could be closed by up to 42%. These results highlight the ability of micro-satellite data to understand yield gaps and their drivers, and can be used to help identify ways to increase production in smallholder systems across the globe.

Yield Drivers Yield Mapping CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MICROSATELLITES YIELD GAP SMALLHOLDERS FOOD PRODUCTION YIELD INCREASES

El camino hacia la sociedad urbana agro industrial. El caso de la ciudad de Mérida de 1864 a 1930

Mercy Eugenia Sandoval Martiñon (2023, [Tesis de maestría])

“La presente tesis busca dar cuenta de los cambios que consolidaron a Mérida como una ciudad agro industrial en el periodo que va de 1864 a 1930. Para ello aborda aquellos factores y elementos sustanciales que transformaron la sociedad urbana durante el auge comercial henequenero de finales del siglo XIX y Principios del siglo XX. El texto se divide en capítulos temáticos que dotan de una vista panorámica par contemplar la sincronía de las conexiones atlánticas caribeñas con sus experiencias particulares y colectivas, la situación de dependencia comercial internacional de la península durante el siglo XIX, los incesantes cambios políticos que acompañaron la consolidación del auge comercial, las principales adecuaciones al mobiliario, ampliación y mejoramiento de los servicios urbanos, cambios en las habilidades, movilidad, higiene y telecomunicaciones, además de un crecimiento comercial e industrial centralizado que situó a Mérida como la principal urbe de la península de Yucatán cuando este era un lugar en disputa. Los parteaguas históricos que delimitan la temporalidad de la investigación son la planeación del primer plano topográfico de la ciudad (1864-1865) y la construcción del primer telégrafo de Sisal a Mérida (1865) y se cierra con la primera gran caída del henequén luego de la primera Guerra Mundial y la publicación de resultados del Quinto Censo de Población mexicano (1930). A través de la revisión de fuentes primarias y secundarias –actas de cabildo del H. Ayuntamiento de Mérida, periódicos, revistas y portuarios comerciales, notas y documentos empresariales privados, censos, fotografías, entre otros-, se comprobaron los procesos de crecimiento urbano como parte de un todo global y regional caribeño, así como la visualización espacial de los comercios e industria meridiana en los albores del siglo XX".

Yucatán - Urbanización - Siglos XIX-XX. Yucatán - Condiciones económicas - Historia - Siglos XIX-XX. Transporte urbano - Yucatán - Mérida - Siglos XIX-XX. Planteamiento regional - Yucatán - Mérida. Mérida (Yucatán) - Política económica - Siglos XIX-XX. Mérida (Yucatán) - Comercio - Siglos XIX-XX. Tesis - Maestría en Historia, Peninsular. CIENCIAS SOCIALES HISTORIA HISTORIA DE PAÍSES HISTORIA LOCAL HISTORIA LOCAL

The input reduction principle of agroecology is wrong when it comes to mineral fertilizer use in sub-Saharan Africa

Gatien Falconnier Marc Corbeels Frédéric Baudron Antoine Couëdel leonard rusinamhodzi bernard vanlauwe Ken Giller (2023, [Artículo])

Can farmers in sub-Saharan Africa (SSA) boost crop yields and improve food availability without using more mineral fertilizer? This question has been at the center of lively debates among the civil society, policy-makers, and in academic editorials. Proponents of the “yes” answer have put forward the “input reduction” principle of agroecology, i.e. by relying on agrobiodiversity, recycling and better efficiency, agroecological practices such as the use of legumes and manure can increase crop productivity without the need for more mineral fertilizer. We reviewed decades of scientific literature on nutrient balances in SSA, biological nitrogen fixation of tropical legumes, manure production and use in smallholder farming systems, and the environmental impact of mineral fertilizer. Our analyses show that more mineral fertilizer is needed in SSA for five reasons: (i) the starting point in SSA is that agricultural production is “agroecological” by default, that is, very low mineral fertilizer use, widespread mixed crop-livestock systems and large crop diversity including legumes, but leading to poor soil fertility as a result of widespread soil nutrient mining, (ii) the nitrogen needs of crops cannot be adequately met solely through biological nitrogen fixation by legumes and recycling of animal manure, (iii) other nutrients like phosphorus and potassium need to be replaced continuously, (iv) mineral fertilizers, if used appropriately, cause little harm to the environment, and (v) reducing the use of mineral fertilizers would hamper productivity gains and contribute indirectly to agricultural expansion and to deforestation. Yet, the agroecological principles directly related to soil fertility—recycling, efficiency, diversity—remain key in improving soil health and nutrient-use efficiency, and are critical to sustaining crop productivity in the long run. We argue for a nuanced position that acknowledges the critical need for more mineral fertilizers in SSA, in combination with the use of agroecological practices and adequate policy support.

Manure Crop Yields Smallholder Farming Systems Environmental Hazards CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA BIOLOGICAL NITROGEN FIXATION LEGUMES NUTRIENT BALANCE SOIL FERTILITY AGROECOLOGY YIELD INCREASES LITERATURE REVIEWS

Smallholder maize yield estimation using satellite data and machine learning in Ethiopia

Zhe Guo Jordan Chamberlin Liangzhi You (2023, [Artículo])

The lack of timely, high-resolution data on agricultural production is a major challenge in developing countries where such information can guide the allocation of scarce resources for food security, agricultural investment, and other objectives. While much research has suggested that remote sensing can potentially help address these gaps, few studies have indicated the immediate potential for large-scale estimations over both time and space. In this study we described a machine learning approach to estimate smallholder maize yield in Ethiopia, using well-measured and broadly distributed ground truth data and freely available spatiotemporal covariates from remote sensing. A neural networks model outperformed other algorithms in our study. Importantly, our work indicates that a model developed and calibrated on a previous year's data could be used to reasonably estimate maize yield in the subsequent year. Our study suggests the feasibility of developing national programs for the routine generation of broad-scale and high-resolution estimates of smallholder maize yield, including seasonal forecasts, on the basis of machine learning algorithms, well-measured ground control data, and currently existing time series satellite data.

Sentinel-2 Smallholder Agriculture Yield Prediction CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA INTENSIFICATION SMALLHOLDERS AGRICULTURE YIELD FORECASTING

Estandarización de nombres comunes de plantas yucatanenses, parte 1: mayas y yucatecos

Jorge Carlos Trejo Torres (2023, [Artículo])

Nombrar plantas es una necesidad para ocuparnos de ellas. En casos afortunados, una especie tiene un solo nombre común, aunque frecuentemente las especies tienen más de un nombre. En la península de Yucatán, los nombres en lengua maya son complejos en escritura y pronunciación. Aunque la estandarización de su escritura se ha trabajado, hoy día es común ver nombres mayas de plantas escritos sin reglas. Entonces, proponemos criterios para estandarizar la escritura o selección de nombres comunes de las plantas regionales. También planteamos que dicha estandarización se integre en medios confiables como bases de datos botánicas regionales.

BASES DE DATOS BOTANICAS CRITERIOS ESPAÑOL YUCATECO NOMENCLATURA FOLCLORICA LENGUA MAYA BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL